add unit-test checking the assertion on unaligned arrays -- checking

that it's triggered when and only when it should.

test/CMakeLists.txt

@@ -159,6 +159,7 @@ ei_add_test(dynalloc)
 ei_add_test(nomalloc)
 ei_add_test(mixingtypes)
 ei_add_test(packetmath)
+ei_add_test(unalignedassert)
 ei_add_test(basicstuff)
 ei_add_test(linearstructure)
 ei_add_test(cwiseop)

test/unalignedassert.cpp

@@ -0,0 +1,105 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra. Eigen itself is part of the KDE project.
+//
+// Copyright (C) 2008 Benoit Jacob <jacob.benoit.1@gmail.com>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#include "main.h"
+
+struct Good1
+{
+  MatrixXd m; // good: m will allocate its own array, taking care of alignment.
+  Good1() : m(20,20) {}
+};
+
+struct Good2
+{
+  Matrix3d m; // good: m's size isn't a multiple of 16 bytes, so m doesn't have to be aligned
+};
+
+struct Good3
+{
+  Vector2f m; // good: same reason
+};
+
+struct Bad4
+{
+  Vector2d m; // bad: sizeof(m)%16==0 so alignment is required
+};
+
+struct Bad5
+{
+  Matrix<float, 2, 6> m; // bad: same reason
+};
+
+struct Bad6
+{
+  Matrix<double, 3, 4> m; // bad: same reason
+};
+
+struct Good7 : Eigen::WithAlignedOperatorNew
+{
+  Vector2d m;
+  float f; // make the struct have sizeof%16!=0 to make it a little more tricky when we allow an array of 2 such objects
+};
+
+struct Good8 : Eigen::WithAlignedOperatorNew
+{
+  float f; // try the f at first -- the EIGEN_ALIGN_128 attribute of m should make that still work
+  Matrix4f m;
+};
+
+template<typename T>
+void check_unalignedassert_good()
+{
+  T *x, *y;
+  x = new T;
+  delete x;
+  y = new T[2];
+  delete[] y;
+}
+
+template<typename T>
+void check_unalignedassert_bad()
+{
+  float buf[1000];
+  float *unaligned = buf;
+  while((reinterpret_cast<size_t>(unaligned)&0xf)==0) ++unaligned; // make sure unaligned is really unaligned
+  T *x = new(static_cast<void*>(unaligned)) T;
+  x->~T();
+}
+
+void unalignedassert()
+{
+  check_unalignedassert_good<Good1>();
+  check_unalignedassert_good<Good2>();
+  check_unalignedassert_good<Good3>();
+  VERIFY_RAISES_ASSERT(check_unalignedassert_bad<Bad4>());
+  VERIFY_RAISES_ASSERT(check_unalignedassert_bad<Bad5>());
+  VERIFY_RAISES_ASSERT(check_unalignedassert_bad<Bad6>());
+  check_unalignedassert_good<Good7>();
+  check_unalignedassert_good<Good8>();
+}
+
+void test_unalignedassert()
+{
+  CALL_SUBTEST(unalignedassert());
+}